Nuclear and particle physics

Question 1

Rutherford scattering experiment lead to discovery of…

Answer 1

nucleus

Question 2

what do the undeflected alpha particles prove

Answer 2

most of the atom is empty space

Question 3

what proportion of alpha particles were deflected in the experiment

Answer 3

1/2000

Question 4

what proportion of alpha particles were deflected more than 90 degrees

Answer 4

1/8000

Question 5

how to estimate the maximum radius of the nucleus

Answer 5

kinetic energy and closest approach

Question 6

what is an isotope

Answer 6

element with same number of protons but different number of neutrons

Question 7

how to work out distance of closest approach

Answer 7

Kinetic energy = Electric potential energy
1/2 mv^2 = Qq/4piE0r^2

Question 8

nuclear radius R equation

Answer 8

R=r0 A^1/3

r0 is a constant (1.2x10^-15)
A is nucleon number

Question 9

define hadron

Answer 9

a particle that experiences both the strong nuclear force and the weak nuclear force

Question 10

define lepton

Answer 10

fundamental particles and don’t experience the strong nuclear force

Question 11

antiparticle of:
proton
electron
neutron
neutrino

Answer 11

antiproton
positron
antineutron
antineutrino

Question 12

name two hadrons

Answer 12

protons and neutrons

Question 13

name two leptons

Answer 13

electrons and neutrinos

Question 14

quark composition of proton

Answer 14

uud

Question 15

quark composition of neutron

Answer 15

udd

Question 16

diameter of atom

Answer 16

10^-10 m

Question 17

diameter of nucleus

Answer 17

10^-15 m

Question 18

Activity of a source

Answer 18

A = λN

Question 19

Half life of an isotope

Answer 19

λt1/2 = ln2

Question 20

Activity at a given time

Answer 20

A=A₀e^-λt

Question 21

Number of undecayed nuclei

Answer 21

N=N₀e^-λt

Question 22

Energy mass equation

Answer 22

E=mc^2

Question 23

what is mass defect

Answer 23

difference between masses of products and final product

Question 24

explain what is meant by the total binding energy of a nucleus

Answer 24

Energy required to disassemble the nucleus into protons and neutrons

Question 25

What’s a moderator

Answer 25

material which slows down neutrons produced by fission

Question 26

what’s a coolant

Answer 26

fluid pumped through core of a reactor to transfer thermal energy from core to the heat exchanger

Question 27

What are control rods

Answer 27

Cadmium rods that are moved in and out of the core to absorb more/less of the neutron to control the rate of fission

Question 28

Two quantities conserved in beta decay

Answer 28

charge
energy/mass

Question 29

What is an alpha particle

Answer 29

Helium nucleus
Two protons, two neutrons